Objective: To study the clinical features of juvenile nephronophthisis and medullary cystic disease and improve the knowledge of the disease. Methods:Retrospectively analyzed the clinical data of 2 patients with juvenile nephronophthisis and medullary cystic disease and reviewed related literatures. Results: Both cases presented at the juveniles stage. The main symptoms were characterized by polyuria, polydipsia, enuresis, growth retardation, anemia and chronic renal failure. One case had pigmentary retinopathy and the other had secondary hyperparathyroid. Laboratory tests showed lower haemoglobin, lower specific gravity of urine. electrolyte disturbance and higher serum creatinine or blood urea nitrogen in both cases. Ultrasound. computerized tomography scanning or magnetic resonance imaging showed multicysts at the corticomedullary border or medullary of the two kidneys. Conclusion: Nephronophthisis and medullary cystic kidney disease is hereditary disease characterized by renal multicysts and latent chronic renal failure. The clinical symptoms are various and sometimes not typical. By studying the clinical features of the disease, we can reduce the possibilities of misdiagnosis and missed diagnosis and increase early diagnostic rate of the disease.